Field of the Invention
The present invention relates to a rendering apparatus and a rendering method for estimating a processing time required for rendering processing.
Description of the Related Art
Conventionally, there has been proposed a technique of notifying a user intending to perform printing processing of a time required for the printing processing. The printing processing includes the following processing. Specifically, page description language (PDL) data inputted with an instruction of the printing processing is analyzed to generate intermediate data; then, bitmap image data is generated from the generated intermediate data; and printing is performed based on the bitmap image data. Generally, processing which requires a long time in the printing processing is the processing of generating the bitmap image data from the intermediate data. In the following description, the time required for the processing of generating the bitmap image data from the intermediate data is referred to as processing time required for the image formation processing or simply image formation time.
Japanese Patent Laid-Open No. 2011-239071 proposes a technique of estimating the aforementioned image formation time from the number and sizes of rendering objects included in rendering information on a page shown by the PDL data.
However, estimation of the image formation time using the aforementioned image formation time estimation technique has a problem that the image formation time cannot be accurately estimated for some of image formation processing methods.
For example, image formation processing using a generally-known scan line method forms an image by performing hidden surface removal for each scan line while omitting image formation of an invisible region of an object hidden by another object overlapping in the foreground. The technique of Japanese Patent Laid-Open No. 2011-239071 performs the estimation simply based on the number and sizes of the rendering objects, and therefore estimates the processing time assuming that an object, which lies behind another object and is not actually formed, is to be formed. Accordingly, this technique has a problem that an accurate image formation time cannot be estimated due to inclusion of a time required for irrelevant data which are eventually hidden (data prevented from being rendered). For example, an image formation time longer than the actual time required for the image formation processing is sometimes estimated.